Buggy code:
public final class LpeSystemUtils { private static final Logger LOGGER = LoggerFactory . getLogger ( LpeSystemUtils . class ) ; private static final String NATIVE_SUBFOLDER = "native" ; private static final String JAVA_LIBRARY_PATH = "java.library.path" ; private static final String KILLSERVICE_CMD_WINDOWS = "net<seq2seq4repair_space>stop<seq2seq4repair_space>" ; private static ExecutorService threadPool ; private static Logger logger = LoggerFactory . getLogger ( LpeSystemUtils . class ) ; private static boolean nativeLibrariesLoaded = false ; private static String systemTempDir = null ; private static String eol ; private static OSType os ; private LpeSystemUtils ( ) { } public static String getEOL ( ) { } public static String getRootFolder ( ) { } public static Future < ? > submitTask ( Runnable command ) { } private static synchronized ExecutorService getThreadPool ( ) { } public static String getRootFolder ( Class < ? > mainClass ) { } public static int exists ( Object obj , Object [ ] array ) { } public static String getOSName ( ) { } public static boolean isMacOS ( ) { } public static boolean isWindowsOS ( ) { } public static boolean isUnix ( ) { } public static void shutdownService ( String serviceName ) throws SystemToolsException { } public static void loadNativeLibraries ( ) { } public static String getSystemTempDir ( ) { } public static String extractFilesFromClasspath ( String srcDirName , String destName , String fileType , ClassLoader classLoader ) throws IOException , URISyntaxException { } public static String extractFilesFromClasspath ( String srcDirName , String destName , String fileType , ClassLoader classloader , boolean timeStamp ) throws IOException , URISyntaxException { } public static void extractJARtoTemp ( URL url , String dirOfInterest , String dest ) throws IOException , URISyntaxException { if ( ! ( url . getProtocol ( ) . equals ( "jar" ) ) ) { throw new IllegalArgumentException ( "Cannot<seq2seq4repair_space>locate<seq2seq4repair_space>the<seq2seq4repair_space>JAR<seq2seq4repair_space>file." ) ; } File tempJarDirFile = new File ( dest ) ; if ( ! ( tempJarDirFile . exists ( ) ) ) { boolean ok = tempJarDirFile . mkdir ( ) ; if ( ! ok ) { LpeSystemUtils . logger . warn ( "Could<seq2seq4repair_space>not<seq2seq4repair_space>create<seq2seq4repair_space>directory<seq2seq4repair_space>{}" , tempJarDirFile . getAbsolutePath ( ) ) ; } } else { FileUtils . cleanDirectory ( tempJarDirFile ) ; } String urlStr = url . getFile ( ) ; if ( urlStr . contains ( "!" ) ) { final int endIndex = urlStr . indexOf ( "!" ) ; urlStr = urlStr . substring ( 0 , endIndex ) ; } URI uri = new URI ( urlStr ) ; final File jarFile = new File ( uri ) ; LpeSystemUtils . logger . debug ( "Unpacking<seq2seq4repair_space>jar<seq2seq4repair_space>file<seq2seq4repair_space>{}..." , jarFile . getAbsolutePath ( ) ) ; JarFile jar = null ; InputStream is = null ; OutputStream fos = null ; try { jar = new JarFile ( jarFile ) ; Enumeration < JarEntry > entries = jar . entries ( ) ; while ( entries . hasMoreElements ( ) ) { JarEntry file = ( ( JarEntry ) ( entries . nextElement ( ) ) ) ; String destFileName = ( dest + ( File . separator ) ) + ( file . getName ( ) ) ; <START_BUG> if ( ( destFileName . indexOf ( dirOfInterest ) ) < 0 ) { <END_BUG> continue ; } LpeSystemUtils . logger . debug ( "unpacking<seq2seq4repair_space>{}..." , file . getName ( ) ) ; File f = new File ( destFileName ) ; if ( file . isDirectory ( ) ) { boolean ok = f . mkdir ( ) ; if ( ! ok ) { LpeSystemUtils . logger . warn ( "Could<seq2seq4repair_space>not<seq2seq4repair_space>create<seq2seq4repair_space>directory<seq2seq4repair_space>{}" , f . getAbsolutePath ( ) ) ; } continue ; } is = new BufferedInputStream ( jar . getInputStream ( file ) ) ; fos = new BufferedOutputStream ( new FileOutputStream ( f ) ) ; LpeStreamUtils . pipe ( is , fos ) ; } LpeSystemUtils . logger . debug ( "Unpacking<seq2seq4repair_space>jar<seq2seq4repair_space>file<seq2seq4repair_space>done." ) ; } catch ( IOException e ) { throw e ; } finally { if ( jar != null ) { jar . close ( ) ; } if ( fos != null ) { fos . close ( ) ; } if ( is != null ) { is . close ( ) ; } } } public static void appendLibraryPath ( String path ) throws Exception { } public static void setLibraryPath ( String path ) throws Exception { } public static void main ( String [ ] args ) { } public static OSType getOperatingSystemType ( ) { } }

Fix:
if ( ( ( destFileName . indexOf ( ( dirOfInterest + ( File . separator ) ) ) ) < 0 ) && ( ( destFileName . indexOf ( ( dirOfInterest + "//" ) ) ) < 0 ) ) {